Researchers Create Embryonic-Like Stem Cells From Human Testes

Oct. 9 -- WEDNESDAY, Oct. 8 (HealthDay News) -- European researchers say they've figured out how to coax sperm-producing testicular cells into embryonic-like stem cells.

The findings are the latest in a flurry of published research that seeks to duplicate embryonic stem cell behavior and biology while sidestepping the political and ethical obstacles associated with their use.

"The ability to make a pluripotent stem cell from an individual without the ethical and immunological problems associated with human embryonic stem cells is a big deal," said Peter J. Donovan,, a stem cell expert at the University of California, Irvine.

The new research was published online Oct. 8 in the journal Nature.

Thomas Skutella of the University of Tubingen in Germany and his colleagues used testicular tissue from 22 men to create what they call "germline stem cells." Essentially, they collected these tissues, isolated the cells that give rise to sperm cells, and then cultured them in growth media containing factors that support the development of human embryonic stem cells. Within a few weeks, the cells took on many of the genetic and growth characteristics of embryonic stem cells.

At the genetic level, for instance, the new cells were more like embryonic stem cells than sperm cells. When injected into immune-compromised mice, they produced teratomas, a tumor that contains many different kinds of cells. When grown in culture dishes, the new cells could be directed to differentiate into muscle, bone, neurons, and pancreatic tissues, the study authors said.

"My summary is, it is a nice paper, they made big progress in getting to a pluripotent cell, and they show pluripotency with a teratoma experiment," said Dr. Gerd Hasenfuss of the University of Gottingen, Germany, who has published papers on converting mouse sperm cells into stem cells.

"But I think we are not completely there where we want to be," he added, "namely at pluripotency absolutely comparable to that of embryonic stem cells." In particular, he noted that the study authors failed to show creation of cells called cardiomyocytes, which cause heart muscle to beat.